I put "i am occasionally sad" and it corrected it to "ocasionally" (which is incorrect).
Typo, fixed. Thanks for reporting.
Why can't it be "At times, I am sad"
Seems correct, reported it.
Is there a difference between using czasem and czasami for "sometimes"?
Not really, just stylistic or personal preference.
So, do Englishmen say "Sometimes I have sorrow" or not?
It's not incorrect but 'I have sorrow' would be odd in 21st century normal speech. It would be more likely to be heard in old songs or poetry.
Niekedy possible too?
It would be easier if smutny meant dirty. Any one have a good mnemonic to remember that smutny means sad?
I'm not good with mnemonics, I just remember or use flashcards. But out of curiosity, why would it be easier with "dirty"?
smut is both a word for dirty and a bacteria that turns wheat bad.